EFFECT OF NONPROTEIN COLLOID ON POSTBURN EDEMA FORMATION IN SOFT-TISSUES AND LUNG

  • 1 January 1984
    • journal article
    • research article
    • Vol. 95  (5) , 593-602
Abstract
The effect of a nonprotein colloid solution, low MW dextran, (LMWD) on edema formation in burned and nonburned soft tissue and lung was studied. Adult sheep with lung and bilateral flank lymph fistulas were given a unilateral 25% to 30% full-thickness burn under ketamine anesthesia and followed for 72 h. Resuscitation (24-h period) was performed with lactated Ringer solution (LR) (n = 9) or 10% LMWD in saline (n = 8) to restore baseline vascular pressures and cardiac output. Interstitial edema and microvascular protein permeability were monitored by lymph flow (.ovrhdot.QL) and lymph to plasma protein ratio, respectively. With LR, .ovrhdot.QL values in nonburned skin and lung were increased 2- to 3-fold in the first 24 h, while with LMWD, values remained at baseline. The nonburn edema with LR was due to the burn-induced hypoproteinemia state. The prevention of this process with LMWD was due to the generation of a 2- to 3-fold increase in the plasma to interstitial colloid osmotic pressure (COP) gradient. Burn .ovrhdot.QL was increased 5-fold in both groups despite a higher COP gradient with LMWD. Net fluid requirements for the 1st 24 h were 75 and 35 ml/kg for animals treated with LR and LMWD, respectively. After cessation of dextran administration in the 2nd 24 h, the COP gradients for the 2 groups were equal but .ovrhdot.QL in nonburned skin and net fluid requirements now increased significantly in the LMWD group. The development of nonburn edema was believed to be due to the persistent hypoproteinemia state. Edema formation in nonburned tissues, which is due to hypoproteinemia, apparently accounts for a substantial amount of the net fluid requirements after thermal injury. This process can be prevented by infusion of a nonprotein colloid as long as the COP gradient is increased. Edema in burned tissue appears to be unaffected by changes in COP.